Cross flow horizontal rotary lawn mower with airfoil blades

Abstract

A lawnmower uses thin, replaceable blades with a hardened cutting edge and a cross-section defining an airfoil. Such blades are held by blade holding elements in a horizontally rotating mower blade assembly. The blade assembly and blade assembly housing are configured in a specialized cross-flow mower assembly to reduce grass leave tip damage, increase cut quality and overall aesthetic appeal, and create a cross-flow air current while consuming less power and providing a reduced environmental impact.

The invention claimed is: 
     
       1. A horizontal rotary lawn mower, comprising:
 (a) a horizontal rotary blade assembly having a length, a diameter, and a plurality of blades, each of said plurality of blades forming an airfoil and each of said plurality of blades comprising a cutting edge and each of the plurality of blades spanning substantially the entire length of the rotary blade assembly, the horizontal rotary blade assembly comprising a plurality of blade holding elements configured to releasably hold each of the plurality of blades in an orientation such, when the horizontal rotary blade assembly is rotated at an operational speed about an axis parallel to a surface being mowed, the airfoil aspect of the plurality of blades generates an airflow sufficient to direct grass clippings; 
 (b) a mower housing having a front, a back, a top surface and a bottom surface, said housing substantially surrounding at least a portion of the horizontal rotary blade assembly, said bottom surface defining an opening; 
 (c) a baffle for dividing said opening into an intake and an exhaust, said intake having a width, said intake width being between 50 and 75 percent of said horizontal rotary blade assembly diameter; and 
 wherein each of the plurality of blade holding elements comprises a retention slot configured to receive a blade cartridge comprising a spring biased locking mechanism. 
 
     
     
       2. The horizontal rotary lawn mower of  claim 1 , wherein said exhaust further comprises an opening length and width, said length being at least substantially equal to or less than said horizontal rotary blade assembly length, and said exhaust opening width being between 50 and 70 percent of said horizontal rotary blade assembly diameter. 
     
     
       3. The horizontal rotary lawn mower of  claim 2 , wherein said horizontal rotary blade assembly defines a cylinder with an axis, a diameter, and a circumference having an arc length of 360 degrees defined by 360 radii, said top most radius being zero, said housing intake opening beginning at between the 225 and 200 degree radii of said horizontal rotary blade assembly and ending at between the 170 and 150 degree radii of said horizontal rotary blade assembly. 
     
     
       4. The horizontal rotary lawn mower of  claim 2 , wherein said horizontal rotary blade assembly defines a cylinder with an axis, a diameter, and a circumference having an arc length of 360 degrees defined by 360 radii, said top most radius being zero, said housing exhaust opening beginning at between the 60 and 80 degree radii of said horizontal rotary blade assembly and ending at between the 120 and 130 degree radii of said horizontal rotary blade assembly. 
     
     
       5. The horizontal rotary lawn mower of  claim 4 , wherein said housing intake opening has an arc length of between 60 and 70 degrees, and said exhaust opening has an arc length of between 50 and 60 degrees. 
     
     
       6. The horizontal rotary lawn mower of  claim 5 , wherein said baffle has at least one dimension approximately equal to the radius of said horizontal rotary blade assembly. 
     
     
       7. The horizontal rotary lawn mower of  claim 1 , wherein said baffle has a curved surface nearest a rotational arc of said horizontal rotary blade assembly which varies in distance from said rotational arc. 
     
     
       8. The horizontal rotary lawn mower of  claim 7 , wherein said opening defines a substantially equal annular space between said housing and said horizontal rotary blade assembly by forming a substantially constant radius from approximately 220 to 355 degrees. 
     
     
       9. The horizontal rotary lawn mower of  claim 8 , wherein said opening distance to said horizontal rotary blade assembly blade arc varies between the arc length defined by the housing bottom surface between approximately 350 and 60 degrees. 
     
     
       10. The horizontal rotary lawn mower of  claim 1 , wherein each of said plurality of blades has maximum thickness of 0.075 inch and the cutting edge of each of said plurality of blades has a hardness of greater than 50 HRC. 
     
     
       11. The horizontal rotary mower of  claim 1 , wherein each of the plurality of blade holding elements comprises a retention slot defining a space conforming to the shape of a blade in the plurality of blades. 
     
     
       12. The horizontal rotary mower of  claim 1 , wherein each of the plurality of blade holding elements comprises retention slot configured to receive a blade cartridge comprising a spring biased locking mechanism.